Osteotomies of the knee are an important technique for treating knee osteoarthritis. In essence, knee osteotomies adjust the geometry of the knee joint so as to transfer weight bearing load from arthritic portions of the joint to relatively unaffected portions of the joint.
Knee osteotomies are also an important technique for addressing abnormal knee geometries, e.g., due to birth defect, injury, etc.
Most knee osteotomies are designed to modify the geometry of the tibia, so as to adjust the manner in which load is transferred across the knee joint.
There are essentially two ways in which to adjust the orientation of the tibia: (i) the so-called “closed wedge” technique; and (ii) the so-called “open wedge” technique.
With the closed wedge technique, a wedge of bone is removed from the upper portion of the tibia, and then the tibia is manipulated so as to close the resulting gap, whereby to re-orient the lower portion of the tibia relative to the tibial plateau and hence adjust the manner in which load is transferred from the femur to the tibia.
With the open wedge technique, a cut is made into the upper portion of the tibia, the tibia is manipulated so as to open a wedge-like opening in the bone, and then the bone is secured in this position (e.g., by screwing metal plates to the bone or by inserting a wedge-shaped implant into the opening in the bone), whereby to re-orient the lower portion of the tibia relative to the tibial plateau and hence adjust the manner in which load is transferred from the femur to the tibia.
While both closed wedge osteotomies and open wedge osteotomies provide substantial benefits to the patient, they are procedurally challenging for the surgeon.
Among other things, with respect to open wedge osteotomies, it can be difficult to properly stabilize the upper and lower portions of the tibia relative to one another, and to properly maintain them in this position, while healing occurs.
In addition, with open wedge osteotomies, the wedge-shaped implants are generally anatomically-specific, in the sense that the size of the implant must be matched to the size of the anatomy and the degree of correction desired. This can present inventory issues.
And, with open wedge osteotomies, the wedge-shaped implants are generally procedure-specific, in the sense that an antero-medial approach may require one configuration for the implant, a lateral approach may require another configuration for the implant, etc. Again, this can present inventory issues.
In addition to the foregoing, open wedge osteotomies may also be performed on locations other than the high tibia. By way of example but not limitation, an open wedge knee osteotomy may be performed on the low femur. By way of further example but not limitation, an open wedge osteotomy may be performed on a joint other than the knee, e.g., an open wedge osteotomy may be performed on the elbow. Again, these open wedge osteotomies may be stabilized with metal plates, wedge-shaped implants, etc. And again, these open wedge osteotomies generally suffer from the aforementioned issues of proper stabilization, size specificity, procedure specificity, etc.
The present invention is directed to open wedge osteotomies in general, both for the knee and for other joints, and is intended to provide a new and improved osteotomy implant which addresses the foregoing issues with the prior art.